/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.solr.handler;

import org.apache.lucene.index.IndexCommit;
import org.apache.lucene.index.IndexDeletionPolicy;
import org.apache.lucene.index.IndexReader;
import org.apache.solr.common.params.CommonParams;
import org.apache.solr.common.params.ModifiableSolrParams;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.FastOutputStream;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.SimpleOrderedMap;
import org.apache.solr.common.util.StrUtils;
import org.apache.solr.core.*;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.response.BinaryQueryResponseWriter;
import org.apache.solr.response.SolrQueryResponse;
import org.apache.solr.search.SolrIndexSearcher;
import org.apache.solr.update.DirectUpdateHandler2;
import org.apache.solr.util.RefCounted;
import org.apache.solr.util.plugin.SolrCoreAware;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.text.NumberFormat;
import java.util.*;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.zip.Adler32;
import java.util.zip.Checksum;
import java.util.zip.DeflaterOutputStream;

/**
 * <p> A Handler which provides a REST API for replication and serves replication requests from Slaves. <p/> </p>
 * <p>When running on the master, it provides the following commands <ol> <li>Get the current replicatable index version
 * (command=indexversion)</li> <li>Get the list of files for a given index version
 * (command=filelist&amp;indexversion=&lt;VERSION&gt;)</li> <li>Get full or a part (chunk) of a given index or a config
 * file (command=filecontent&amp;file=&lt;FILE_NAME&gt;) You can optionally specify an offset and length to get that
 * chunk of the file. You can request a configuration file by using "cf" parameter instead of the "file" parameter.</li>
 * <li>Get status/statistics (command=details)</li> </ol> </p> <p>When running on the slave, it provides the following
 * commands <ol> <li>Perform a snap pull now (command=snappull)</li> <li>Get status/statistics (command=details)</li>
 * <li>Abort a snap pull (command=abort)</li> <li>Enable/Disable polling the master for new versions (command=enablepoll
 * or command=disablepoll)</li> </ol> </p>
 *
 * @version $Id: ReplicationHandler.java 1203003 2011-11-17 01:50:33Z hossman $
 * @since solr 1.4
 */

public class ReplicationHandler extends RequestHandlerBase implements SolrCoreAware{

	@Override
	public void inform(SolrCore core) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void handleRequestBody(SolrQueryRequest req, SolrQueryResponse rsp)
			throws Exception {
		// TODO Auto-generated method stub
		
	}

	@Override
	public String getDescription() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public String getSourceId() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public String getSource() {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public String getVersion() {
		// TODO Auto-generated method stub
		return null;
	}}
//
//public class ReplicationHandler extends RequestHandlerBase implements SolrCoreAware {
//  private static final Logger LOG = LoggerFactory.getLogger(ReplicationHandler.class.getName());
//  SolrCore core;
//
//  private SnapPuller snapPuller;
//
//  private ReentrantLock snapPullLock = new ReentrantLock();
//
//  private String includeConfFiles;
//
//  private NamedList<String> confFileNameAlias = new NamedList<String>();
//
//  private boolean isMaster = false;
//
//  private boolean isSlave = false;
//
//  private boolean replicateOnOptimize = false;
//
//  private boolean replicateOnCommit = false;
//
//  private boolean replicateOnStart = false;
//
//  private int numTimesReplicated = 0;
//
//  private final Map<String, FileInfo> confFileInfoCache = new HashMap<String, FileInfo>();
//
//  private Integer reserveCommitDuration = SnapPuller.readInterval("00:00:10");
//
//  private volatile IndexCommit indexCommitPoint;
//
//  volatile NamedList snapShootDetails;
//
//  private AtomicBoolean replicationEnabled = new AtomicBoolean(true);
//
//  @Override
//  public void handleRequestBody(SolrQueryRequest req, SolrQueryResponse rsp) throws Exception {
//    rsp.setHttpCaching(false);
//    final SolrParams solrParams = req.getParams();
//    String command = solrParams.get(COMMAND);
//    if (command == null) {
//      rsp.add(STATUS, OK_STATUS);
//      rsp.add("message", "No command");
//      return;
//    }
//    // This command does not give the current index version of the master
//    // It gives the current 'replicateable' index version
//    if (command.equals(CMD_INDEX_VERSION)) {
//      IndexCommit commitPoint = indexCommitPoint;  // make a copy so it won't change
//      if (commitPoint != null && replicationEnabled.get()) {
//        //
//        // There is a race condition here.  The commit point may be changed / deleted by the time
//        // we get around to reserving it.  This is a very small window though, and should not result
//        // in a catastrophic failure, but will result in the client getting an empty file list for
//        // the CMD_GET_FILE_LIST command.
//        //
//        core.getDeletionPolicy().setReserveDuration(commitPoint.getVersion(), reserveCommitDuration);
//        rsp.add(CMD_INDEX_VERSION, commitPoint.getVersion());
//        rsp.add(GENERATION, commitPoint.getGeneration());
//      } else {
//        // This happens when replication is not configured to happen after startup and no commit/optimize
//        // has happened yet.
//        rsp.add(CMD_INDEX_VERSION, 0L);
//        rsp.add(GENERATION, 0L);
//      }
//    } else if (command.equals(CMD_GET_FILE)) {
//      getFileStream(solrParams, rsp);
//    } else if (command.equals(CMD_GET_FILE_LIST)) {
//      getFileList(solrParams, rsp);
//    } else if (command.equalsIgnoreCase(CMD_BACKUP)) {
//      doSnapShoot(new ModifiableSolrParams(solrParams), rsp,req);
//      rsp.add(STATUS, OK_STATUS);
//    } else if (command.equalsIgnoreCase(CMD_FETCH_INDEX)) {
//      String masterUrl = solrParams.get(MASTER_URL);
//      if (!isSlave && masterUrl == null) {
//        rsp.add(STATUS,ERR_STATUS);
//        rsp.add("message","No slave configured or no 'masterUrl' Specified");
//        return;
//      }
//      final SolrParams paramsCopy = new ModifiableSolrParams(solrParams);
//      new Thread() {
//        @Override
//        public void run() {
//          doFetch(paramsCopy);
//        }
//      }.start();
//      rsp.add(STATUS, OK_STATUS);
//    } else if (command.equalsIgnoreCase(CMD_DISABLE_POLL)) {
//      if (snapPuller != null){
//        snapPuller.disablePoll();
//        rsp.add(STATUS, OK_STATUS);
//      } else {
//        rsp.add(STATUS, ERR_STATUS);
//        rsp.add("message","No slave configured");
//      }
//    } else if (command.equalsIgnoreCase(CMD_ENABLE_POLL)) {
//      if (snapPuller != null){
//        snapPuller.enablePoll();
//        rsp.add(STATUS, OK_STATUS);
//      }else {
//        rsp.add(STATUS,ERR_STATUS);
//        rsp.add("message","No slave configured");
//      }
//    } else if (command.equalsIgnoreCase(CMD_ABORT_FETCH)) {
//      SnapPuller temp = tempSnapPuller;
//      if (temp != null){
//        temp.abortPull();
//        rsp.add(STATUS, OK_STATUS);
//      } else {
//        rsp.add(STATUS,ERR_STATUS);
//        rsp.add("message","No slave configured");
//      }
//    } else if (command.equals(CMD_FILE_CHECKSUM)) {
//      // this command is not used by anyone
//      getFileChecksum(solrParams, rsp);
//    } else if (command.equals(CMD_SHOW_COMMITS)) {
//      rsp.add(CMD_SHOW_COMMITS, getCommits());
//    } else if (command.equals(CMD_DETAILS)) {
//      rsp.add(CMD_DETAILS, getReplicationDetails(solrParams.getBool("slave",true)));
//      RequestHandlerUtils.addExperimentalFormatWarning(rsp);
//    } else if (CMD_ENABLE_REPL.equalsIgnoreCase(command)) {
//      replicationEnabled.set(true);
//      rsp.add(STATUS, OK_STATUS);
//    } else if (CMD_DISABLE_REPL.equalsIgnoreCase(command)) {
//      replicationEnabled.set(false);
//      rsp.add(STATUS, OK_STATUS);
//    }
//  }
//
//  private List<NamedList> getCommits() {
//    Map<Long, IndexCommit> commits = core.getDeletionPolicy().getCommits();
//    List<NamedList> l = new ArrayList<NamedList>();
//
//    for (IndexCommit c : commits.values()) {
//      try {
//        NamedList nl = new NamedList();
//        nl.add("indexVersion", c.getVersion());
//        nl.add(GENERATION, c.getGeneration());
//        nl.add(CMD_GET_FILE_LIST, c.getFileNames());
//        l.add(nl);
//      } catch (IOException e) {
//        LOG.warn("Exception while reading files for commit " + c, e);
//      }
//    }
//    return l;
//  }
//
//  /**
//   * Gets the checksum of a file
//   */
//  private void getFileChecksum(SolrParams solrParams, SolrQueryResponse rsp) {
//    Checksum checksum = new Adler32();
//    File dir = new File(core.getIndexDir());
//    rsp.add(CHECKSUM, getCheckSums(solrParams.getParams(FILE), dir, checksum));
//    dir = new File(core.getResourceLoader().getConfigDir());
//    rsp.add(CONF_CHECKSUM, getCheckSums(solrParams.getParams(CONF_FILE_SHORT), dir, checksum));
//  }
//
//  private Map<String, Long> getCheckSums(String[] files, File dir, Checksum checksum) {
//    Map<String, Long> checksumMap = new HashMap<String, Long>();
//    if (files == null || files.length == 0)
//      return checksumMap;
//    for (String file : files) {
//      File f = new File(dir, file);
//      Long checkSumVal = getCheckSum(checksum, f);
//      if (checkSumVal != null)
//        checksumMap.put(file, checkSumVal);
//    }
//    return checksumMap;
//  }
//
//  static Long getCheckSum(Checksum checksum, File f) {
//    FileInputStream fis = null;
//    checksum.reset();
//    byte[] buffer = new byte[1024 * 1024];
//    int bytesRead;
//    try {
//      fis = new FileInputStream(f);
//      while ((bytesRead = fis.read(buffer)) >= 0)
//        checksum.update(buffer, 0, bytesRead);
//      return checksum.getValue();
//    } catch (Exception e) {
//      LOG.warn("Exception in finding checksum of " + f, e);
//    } finally {
//      IOUtils.closeQuietly(fis);
//    }
//    return null;
//  }
//
//  private volatile SnapPuller tempSnapPuller;
//
//  void doFetch(SolrParams solrParams) {
//    String masterUrl = solrParams == null ? null : solrParams.get(MASTER_URL);
//    if (!snapPullLock.tryLock())
//      return;
//    try {
//      tempSnapPuller = snapPuller;
//      if (masterUrl != null) {
//        NamedList<Object> nl = solrParams.toNamedList();
//        nl.remove(SnapPuller.POLL_INTERVAL);
//        tempSnapPuller = new SnapPuller(nl, this, core);
//      }
//      tempSnapPuller.fetchLatestIndex(core);
//    } catch (Exception e) {
//      LOG.error("SnapPull failed ", e);
//    } finally {
//      tempSnapPuller = snapPuller;
//      snapPullLock.unlock();
//    }
//  }
//
//  boolean isReplicating() {
//    return snapPullLock.isLocked();
//  }
//
//  private void doSnapShoot(SolrParams params, SolrQueryResponse rsp, SolrQueryRequest req) {
//    try {
//      int numberToKeep = params.getInt(NUMBER_BACKUPS_TO_KEEP, Integer.MAX_VALUE);
//      IndexDeletionPolicyWrapper delPolicy = core.getDeletionPolicy();
//      IndexCommit indexCommit = delPolicy.getLatestCommit();
//      
//      if(indexCommit == null) {
//        indexCommit = req.getSearcher().getReader().getIndexCommit();
//      }
//      
//      // small race here before the commit point is saved
//      new SnapShooter(core, params.get("location")).createSnapAsync(indexCommit, numberToKeep, this);
//      
//    } catch (Exception e) {
//      LOG.warn("Exception during creating a snapshot", e);
//      rsp.add("exception", e);
//    }
//  }
//
//  /**
//   * This method adds an Object of FileStream to the resposnse . The FileStream implements a custom protocol which is
//   * understood by SnapPuller.FileFetcher
//   *
//   * @see org.apache.solr.handler.SnapPuller.FileFetcher
//   */
//  private void getFileStream(SolrParams solrParams, SolrQueryResponse rsp) {
//    ModifiableSolrParams rawParams = new ModifiableSolrParams(solrParams);
//    rawParams.set(CommonParams.WT, FILE_STREAM);
//    rsp.add(FILE_STREAM, new FileStream(solrParams));
//  }
//
//  @SuppressWarnings("unchecked")
//  private void getFileList(SolrParams solrParams, SolrQueryResponse rsp) {
//    String v = solrParams.get(CMD_INDEX_VERSION);
//    if (v == null) {
//      rsp.add("status", "no indexversion specified");
//      return;
//    }
//    long version = Long.parseLong(v);
//    IndexCommit commit = core.getDeletionPolicy().getCommitPoint(version);
//    if (commit == null) {
//      rsp.add("status", "invalid indexversion");
//      return;
//    }
//    // reserve the indexcommit for sometime
//    core.getDeletionPolicy().setReserveDuration(version, reserveCommitDuration);
//    List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
//    try {
//      //get all the files in the commit
//      //use a set to workaround possible Lucene bug which returns same file name multiple times
//      Collection<String> files = new HashSet<String>(commit.getFileNames());
//      for (String fileName : files) {
//        if(fileName.endsWith(".lock")) continue;
//        File file = new File(core.getIndexDir(), fileName);
//        Map<String, Object> fileMeta = getFileInfo(file);
//        result.add(fileMeta);
//      }
//    } catch (IOException e) {
//      rsp.add("status", "unable to get file names for given indexversion");
//      rsp.add("exception", e);
//      LOG.warn("Unable to get file names for indexCommit version: "
//               + version, e);
//    }
//    rsp.add(CMD_GET_FILE_LIST, result);
//    if (confFileNameAlias.size() < 1)
//      return;
//    LOG.debug("Adding config files to list: " + includeConfFiles);
//    //if configuration files need to be included get their details
//    rsp.add(CONF_FILES, getConfFileInfoFromCache(confFileNameAlias, confFileInfoCache));
//  }
//
//  /**
//   * For configuration files, checksum of the file is included because, unlike index files, they may have same content
//   * but different timestamps.
//   * <p/>
//   * The local conf files information is cached so that everytime it does not have to compute the checksum. The cache is
//   * refreshed only if the lastModified of the file changes
//   */
//  List<Map<String, Object>> getConfFileInfoFromCache(NamedList<String> nameAndAlias,
//                                                     final Map<String, FileInfo> confFileInfoCache) {
//    List<Map<String, Object>> confFiles = new ArrayList<Map<String, Object>>();
//    synchronized (confFileInfoCache) {
//      File confDir = new File(core.getResourceLoader().getConfigDir());
//      Checksum checksum = null;
//      for (int i = 0; i < nameAndAlias.size(); i++) {
//        String cf = nameAndAlias.getName(i);
//        File f = new File(confDir, cf);
//        if (!f.exists() || f.isDirectory()) continue; //must not happen
//        FileInfo info = confFileInfoCache.get(cf);
//        if (info == null || info.lastmodified != f.lastModified() || info.size != f.length()) {
//          if (checksum == null) checksum = new Adler32();
//          info = new FileInfo(f.lastModified(), cf, f.length(), getCheckSum(checksum, f));
//          confFileInfoCache.put(cf, info);
//        }
//        Map<String, Object> m = info.getAsMap();
//        if (nameAndAlias.getVal(i) != null) m.put(ALIAS, nameAndAlias.getVal(i));
//        confFiles.add(m);
//      }
//    }
//    return confFiles;
//  }
//
//  static class FileInfo {
//    long lastmodified;
//    String name;
//    long size;
//    long checksum;
//
//    public FileInfo(long lasmodified, String name, long size, long checksum) {
//      this.lastmodified = lasmodified;
//      this.name = name;
//      this.size = size;
//      this.checksum = checksum;
//    }
//
//    Map<String, Object> getAsMap() {
//      Map<String, Object> map = new HashMap<String, Object>();
//      map.put(NAME, name);
//      map.put(SIZE, size);
//      map.put(LAST_MODIFIED, lastmodified);
//      map.put(CHECKSUM, checksum);
//      return map;
//    }
//  }
//
//  void disablePoll() {
//    if (isSlave)
//      snapPuller.disablePoll();
//  }
//
//  void enablePoll() {
//    if (isSlave)
//      snapPuller.enablePoll();
//  }
//
//  boolean isPollingDisabled() {
//    return snapPuller.isPollingDisabled();
//  }
//
//  int getTimesReplicatedSinceStartup() {
//    return numTimesReplicated;
//  }
//
//  void setTimesReplicatedSinceStartup() {
//    numTimesReplicated++;
//  }
//
//  long getIndexSize() {
//    return computeIndexSize(new File(core.getIndexDir()));
//  }
//
//  private long computeIndexSize(File f) {
//    if (f.isFile())
//      return f.length();
//    File[] files = f.listFiles();
//    long size = 0;
//    if (files != null && files.length > 0) {
//      for (File file : files) size += file.length();
//    }
//    return size;
//  }
//
//  /**
//   * Collects the details such as name, size ,lastModified of a file
//   */
//  private Map<String, Object> getFileInfo(File file) {
//    Map<String, Object> fileMeta = new HashMap<String, Object>();
//    fileMeta.put(NAME, file.getName());
//    fileMeta.put(SIZE, file.length());
//    fileMeta.put(LAST_MODIFIED, file.lastModified());
//    return fileMeta;
//  }
//
//  @Override
//  public String getDescription() {
//    return "ReplicationHandler provides replication of index and configuration files from Master to Slaves";
//  }
//
//  @Override
//  public String getSourceId() {
//    return "$Id: ReplicationHandler.java 1203003 2011-11-17 01:50:33Z hossman $";
//  }
//
//  @Override
//  public String getSource() {
//    return "$URL: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_3_5/solr/core/src/java/org/apache/solr/handler/ReplicationHandler.java $";
//  }
//
//  @Override
//  public String getVersion() {
//    return "$Revision: 1203003 $";
//  }
//
//  String readableSize(long size) {
//    NumberFormat formatter = NumberFormat.getNumberInstance();
//    formatter.setMaximumFractionDigits(2);
//    if (size / (1024 * 1024 * 1024) > 0) {
//      return formatter.format(size * 1.0d / (1024 * 1024 * 1024)) + " GB";
//    } else if (size / (1024 * 1024) > 0) {
//      return formatter.format(size * 1.0d / (1024 * 1024)) + " MB";
//    } else if (size / 1024 > 0) {
//      return formatter.format(size * 1.0d / 1024) + " KB";
//    } else {
//      return String.valueOf(size) + " bytes";
//    }
//  }
//
//  private long[] getIndexVersion() {
//    long version[] = new long[2];
//    RefCounted<SolrIndexSearcher> searcher = core.getSearcher();
//    try {
//      version[0] = searcher.get().getReader().getIndexCommit().getVersion();
//      version[1] = searcher.get().getReader().getIndexCommit().getGeneration();
//    } catch (IOException e) {
//      LOG.warn("Unable to get index version : ", e);
//    } finally {
//      searcher.decref();
//    }
//    return version;
//  }
//
//  @Override
//  @SuppressWarnings("unchecked")
//  public NamedList getStatistics() {
//    NamedList list = super.getStatistics();
//    if (core != null) {
//      list.add("indexSize", readableSize(getIndexSize()));
//      long[] versionGen = getIndexVersion();
//      list.add("indexVersion", versionGen[0]);
//      list.add(GENERATION, versionGen[1]);
//
//      list.add("indexPath", core.getIndexDir());
//      list.add("isMaster", String.valueOf(isMaster));
//      list.add("isSlave", String.valueOf(isSlave));
//
//      SnapPuller snapPuller = tempSnapPuller;
//      if (snapPuller != null) {
//        list.add(MASTER_URL, snapPuller.getMasterUrl());
//        if (snapPuller.getPollInterval() != null) {
//          list.add(SnapPuller.POLL_INTERVAL, snapPuller.getPollInterval());
//        }
//        list.add("isPollingDisabled", String.valueOf(isPollingDisabled()));
//        list.add("isReplicating", String.valueOf(isReplicating()));
//        long elapsed = getTimeElapsed(snapPuller);
//        long val = SnapPuller.getTotalBytesDownloaded(snapPuller);
//        if (elapsed > 0) {
//          list.add("timeElapsed", elapsed);
//          list.add("bytesDownloaded", val);
//          list.add("downloadSpeed", val / elapsed);
//        }
//        Properties props = loadReplicationProperties();
//        addVal(list, SnapPuller.PREVIOUS_CYCLE_TIME_TAKEN, props, Long.class);
//        addVal(list, SnapPuller.INDEX_REPLICATED_AT, props, Date.class);
//        addVal(list, SnapPuller.CONF_FILES_REPLICATED_AT, props, Date.class);
//        addVal(list, SnapPuller.REPLICATION_FAILED_AT, props, Date.class);
//        addVal(list, SnapPuller.TIMES_FAILED, props, Integer.class);
//        addVal(list, SnapPuller.TIMES_INDEX_REPLICATED, props, Integer.class);
//        addVal(list, SnapPuller.LAST_CYCLE_BYTES_DOWNLOADED, props, Long.class);
//        addVal(list, SnapPuller.TIMES_CONFIG_REPLICATED, props, Integer.class);
//        addVal(list, SnapPuller.CONF_FILES_REPLICATED, props, String.class);
//      }
//      if (isMaster) {
//        if (includeConfFiles != null) list.add("confFilesToReplicate", includeConfFiles);
//        list.add(REPLICATE_AFTER, getReplicateAfterStrings());
//        list.add("replicationEnabled", String.valueOf(replicationEnabled.get()));
//      }
//    }
//    return list;
//  }
//
//  /**
//   * Used for showing statistics and progress information.
//   *
//   * @param showSlaveDetails
//   */
//  private NamedList<Object> getReplicationDetails(boolean showSlaveDetails) {
//    NamedList<Object> details = new SimpleOrderedMap<Object>();
//    NamedList<Object> master = new SimpleOrderedMap<Object>();
//    NamedList<Object> slave = new SimpleOrderedMap<Object>();
//
//    details.add("indexSize", readableSize(getIndexSize()));
//    details.add("indexPath", core.getIndexDir());
//    details.add(CMD_SHOW_COMMITS, getCommits());
//    details.add("isMaster", String.valueOf(isMaster));
//    details.add("isSlave", String.valueOf(isSlave));
//    long[] versionAndGeneration = getIndexVersion();
//    details.add("indexVersion", versionAndGeneration[0]);
//    details.add(GENERATION, versionAndGeneration[1]);
//
//    IndexCommit commit = indexCommitPoint;  // make a copy so it won't change
//
//    if (isMaster) {
//      if (includeConfFiles != null) master.add(CONF_FILES, includeConfFiles);
//      master.add(REPLICATE_AFTER, getReplicateAfterStrings());
//      master.add("replicationEnabled", String.valueOf(replicationEnabled.get()));
//    }
//
//    if (isMaster && commit != null) {
//      master.add("replicatableIndexVersion", commit.getVersion());
//      master.add("replicatableGeneration", commit.getGeneration());
//    }
//
//    SnapPuller snapPuller = tempSnapPuller;
//    if (showSlaveDetails && snapPuller != null) {
//      Properties props = loadReplicationProperties();
//      try {
//        NamedList<String> command = new NamedList<String>();
//        command.add(COMMAND, CMD_DETAILS);
//        command.add("slave", "false");
//        NamedList nl = snapPuller.getCommandResponse(command);
//        slave.add("masterDetails", nl.get(CMD_DETAILS));
//      } catch (Exception e) {
//        LOG.warn("Exception while invoking 'details' method for replication on master ", e);
//        slave.add(ERR_STATUS, "invalid_master");
//      }
//      slave.add(MASTER_URL, snapPuller.getMasterUrl());
//      if (snapPuller.getPollInterval() != null) {
//        slave.add(SnapPuller.POLL_INTERVAL, snapPuller.getPollInterval());
//      }
//      if (snapPuller.getNextScheduledExecTime() != null && !isPollingDisabled()) {
//        slave.add(NEXT_EXECUTION_AT, new Date(snapPuller.getNextScheduledExecTime()).toString());
//      } else if (isPollingDisabled()) {
//        slave.add(NEXT_EXECUTION_AT, "Polling disabled");
//      }
//      addVal(slave, SnapPuller.INDEX_REPLICATED_AT, props, Date.class);
//      addVal(slave, SnapPuller.INDEX_REPLICATED_AT_LIST, props, List.class);
//      addVal(slave, SnapPuller.REPLICATION_FAILED_AT_LIST, props, List.class);
//      addVal(slave, SnapPuller.TIMES_INDEX_REPLICATED, props, Integer.class);
//      addVal(slave, SnapPuller.CONF_FILES_REPLICATED, props, Integer.class);
//      addVal(slave, SnapPuller.TIMES_CONFIG_REPLICATED, props, Integer.class);
//      addVal(slave, SnapPuller.CONF_FILES_REPLICATED_AT, props, Integer.class);
//      addVal(slave, SnapPuller.LAST_CYCLE_BYTES_DOWNLOADED, props, Long.class);
//      addVal(slave, SnapPuller.TIMES_FAILED, props, Integer.class);
//      addVal(slave, SnapPuller.REPLICATION_FAILED_AT, props, Date.class);
//      addVal(slave, SnapPuller.PREVIOUS_CYCLE_TIME_TAKEN, props, Long.class);
//
//      slave.add("isPollingDisabled", String.valueOf(isPollingDisabled()));
//      boolean isReplicating = isReplicating();
//      slave.add("isReplicating", String.valueOf(isReplicating));
//      if (isReplicating) {
//        try {
//          long bytesToDownload = 0;
//          List<String> filesToDownload = new ArrayList<String>();
//          for (Map<String, Object> file : snapPuller.getFilesToDownload()) {
//            filesToDownload.add((String) file.get(NAME));
//            bytesToDownload += (Long) file.get(SIZE);
//          }
//
//          //get list of conf files to download
//          for (Map<String, Object> file : snapPuller.getConfFilesToDownload()) {
//            filesToDownload.add((String) file.get(NAME));
//            bytesToDownload += (Long) file.get(SIZE);
//          }
//
//          slave.add("filesToDownload", filesToDownload);
//          slave.add("numFilesToDownload", String.valueOf(filesToDownload.size()));
//          slave.add("bytesToDownload", readableSize(bytesToDownload));
//
//          long bytesDownloaded = 0;
//          List<String> filesDownloaded = new ArrayList<String>();
//          for (Map<String, Object> file : snapPuller.getFilesDownloaded()) {
//            filesDownloaded.add((String) file.get(NAME));
//            bytesDownloaded += (Long) file.get(SIZE);
//          }
//
//          //get list of conf files downloaded
//          for (Map<String, Object> file : snapPuller.getConfFilesDownloaded()) {
//            filesDownloaded.add((String) file.get(NAME));
//            bytesDownloaded += (Long) file.get(SIZE);
//          }
//
//          Map<String, Object> currentFile = snapPuller.getCurrentFile();
//          String currFile = null;
//          long currFileSize = 0, currFileSizeDownloaded = 0;
//          float percentDownloaded = 0;
//          if (currentFile != null) {
//            currFile = (String) currentFile.get(NAME);
//            currFileSize = (Long) currentFile.get(SIZE);
//            if (currentFile.containsKey("bytesDownloaded")) {
//              currFileSizeDownloaded = (Long) currentFile.get("bytesDownloaded");
//              bytesDownloaded += currFileSizeDownloaded;
//              if (currFileSize > 0)
//                percentDownloaded = (currFileSizeDownloaded * 100) / currFileSize;
//            }
//          }
//          slave.add("filesDownloaded", filesDownloaded);
//          slave.add("numFilesDownloaded", String.valueOf(filesDownloaded.size()));
//
//          long estimatedTimeRemaining = 0;
//
//          if (snapPuller.getReplicationStartTime() > 0) {
//            slave.add("replicationStartTime", new Date(snapPuller.getReplicationStartTime()).toString());
//          }
//          long elapsed = getTimeElapsed(snapPuller);
//          slave.add("timeElapsed", String.valueOf(elapsed) + "s");
//
//          if (bytesDownloaded > 0)
//            estimatedTimeRemaining = ((bytesToDownload - bytesDownloaded) * elapsed) / bytesDownloaded;
//          float totalPercent = 0;
//          long downloadSpeed = 0;
//          if (bytesToDownload > 0)
//            totalPercent = (bytesDownloaded * 100) / bytesToDownload;
//          if (elapsed > 0)
//            downloadSpeed = (bytesDownloaded / elapsed);
//          if (currFile != null)
//            slave.add("currentFile", currFile);
//          slave.add("currentFileSize", readableSize(currFileSize));
//          slave.add("currentFileSizeDownloaded", readableSize(currFileSizeDownloaded));
//          slave.add("currentFileSizePercent", String.valueOf(percentDownloaded));
//          slave.add("bytesDownloaded", readableSize(bytesDownloaded));
//          slave.add("totalPercent", String.valueOf(totalPercent));
//          slave.add("timeRemaining", String.valueOf(estimatedTimeRemaining) + "s");
//          slave.add("downloadSpeed", readableSize(downloadSpeed));
//        } catch (Exception e) {
//          LOG.error("Exception while writing replication details: ", e);
//        }
//      }
//    }
//
//    if (isMaster)
//      details.add("master", master);
//    if (isSlave && showSlaveDetails)
//      details.add("slave", slave);
//    
//    NamedList snapshotStats = snapShootDetails;
//    if (snapshotStats != null)
//      details.add(CMD_BACKUP, snapshotStats);
//    
//    return details;
//  }
//
//  private void addVal(NamedList nl, String key, Properties props, Class clzz) {
//    String s = props.getProperty(key);
//    if (s == null || s.trim().length() == 0) return;
//    if (clzz == Date.class) {
//      try {
//        Long l = Long.parseLong(s);
//        nl.add(key, new Date(l).toString());
//      } catch (NumberFormatException e) {/*no op*/ }
//    } else if (clzz == List.class) {
//      String ss[] = s.split(",");
//      List<String> l = new ArrayList<String>();
//      for (int i = 0; i < ss.length; i++) {
//        l.add(new Date(Long.valueOf(ss[i])).toString());
//      }
//      nl.add(key, l);
//    } else {
//      nl.add(key, s);
//    }
//
//  }
//
//  private List<String> getReplicateAfterStrings() {
//    List<String> replicateAfter = new ArrayList<String>();
//    if (replicateOnCommit)
//      replicateAfter.add("commit");
//    if (replicateOnOptimize)
//      replicateAfter.add("optimize");
//    if (replicateOnStart)
//      replicateAfter.add("startup");
//    return replicateAfter;
//  }
//
//  private long getTimeElapsed(SnapPuller snapPuller) {
//    long timeElapsed = 0;
//    if (snapPuller.getReplicationStartTime() > 0)
//      timeElapsed = (System.currentTimeMillis() - snapPuller.getReplicationStartTime()) / 1000;
//    return timeElapsed;
//  }
//
//  Properties loadReplicationProperties() {
//    FileInputStream inFile = null;
//    Properties props = new Properties();
//    try {
//      File f = new File(core.getDataDir(), SnapPuller.REPLICATION_PROPERTIES);
//      if (f.exists()) {
//        inFile = new FileInputStream(f);
//        props.load(inFile);
//      }
//    } catch (Exception e) {
//      LOG.warn("Exception while reading " + SnapPuller.REPLICATION_PROPERTIES);
//    } finally {
//      IOUtils.closeQuietly(inFile);
//    }
//    return props;
//  }
//
//
//  void refreshCommitpoint() {
//    IndexCommit commitPoint = core.getDeletionPolicy().getLatestCommit();
//    if(replicateOnCommit || (replicateOnOptimize && commitPoint.getSegmentCount() == 1)) {
//      indexCommitPoint = commitPoint;
//    }
//  }
//
//  @SuppressWarnings("unchecked")
//  public void inform(SolrCore core) {
//    this.core = core;
//    registerFileStreamResponseWriter();
//    registerCloseHook();
//    NamedList slave = (NamedList) initArgs.get("slave");
//    boolean enableSlave = isEnabled( slave );
//    if (enableSlave) {
//      tempSnapPuller = snapPuller = new SnapPuller(slave, this, core);
//      isSlave = true;
//    }
//    NamedList master = (NamedList) initArgs.get("master");
//    boolean enableMaster = isEnabled( master );
//    if (enableMaster) {
//      includeConfFiles = (String) master.get(CONF_FILES);
//      if (includeConfFiles != null && includeConfFiles.trim().length() > 0) {
//        List<String> files = Arrays.asList(includeConfFiles.split(","));
//        for (String file : files) {
//          if (file.trim().length() == 0) continue;
//          String[] strs = file.split(":");
//          // if there is an alias add it or it is null
//          confFileNameAlias.add(strs[0], strs.length > 1 ? strs[1] : null);
//        }
//        LOG.info("Replication enabled for following config files: " + includeConfFiles);
//      }
//      List backup = master.getAll("backupAfter");
//      boolean backupOnCommit = backup.contains("commit");
//      boolean backupOnOptimize = !backupOnCommit && backup.contains("optimize");
//      List replicateAfter = master.getAll(REPLICATE_AFTER);
//      replicateOnCommit = replicateAfter.contains("commit");
//      replicateOnOptimize = !replicateOnCommit && replicateAfter.contains("optimize");
//
//      // if we only want to replicate on optimize, we need the deletion policy to
//      // save the last optimized commit point.
//      if (replicateOnOptimize) {
//        IndexDeletionPolicyWrapper wrapper = core.getDeletionPolicy();
//        IndexDeletionPolicy policy = wrapper == null ? null : wrapper.getWrappedDeletionPolicy();
//        if (policy instanceof SolrDeletionPolicy) {
//          SolrDeletionPolicy solrPolicy = (SolrDeletionPolicy)policy;
//          if (solrPolicy.getMaxOptimizedCommitsToKeep() < 1) {
//            solrPolicy.setMaxOptimizedCommitsToKeep(1);
//          }
//        } else {
//          LOG.warn("Replication can't call setMaxOptimizedCommitsToKeep on " + policy);
//        }
//      }
//
//      if (replicateOnOptimize || backupOnOptimize) {
//        core.getUpdateHandler().registerOptimizeCallback(getEventListener(backupOnOptimize, replicateOnOptimize));
//      }
//      if (replicateOnCommit || backupOnCommit) {
//        replicateOnCommit = true;
//        core.getUpdateHandler().registerCommitCallback(getEventListener(backupOnCommit, replicateOnCommit));
//      }
//      if (replicateAfter.contains("startup")) {
//        replicateOnStart = true;
//        RefCounted<SolrIndexSearcher> s = core.getNewestSearcher(false);
//        try {
//          IndexReader reader = s==null ? null : s.get().getReader();
//          if (reader!=null && reader.getIndexCommit() != null && reader.getIndexCommit().getGeneration() != 1L) {
//            try {
//              if(replicateOnOptimize){
//                Collection<IndexCommit> commits = IndexReader.listCommits(reader.directory());
//                for (IndexCommit ic : commits) {
//                  if(ic.getSegmentCount() == 1){
//                    if(indexCommitPoint == null || indexCommitPoint.getVersion() < ic.getVersion()) indexCommitPoint = ic;
//                  }
//                }
//              } else{
//                indexCommitPoint = reader.getIndexCommit();
//              }
//            } finally {
//              // We don't need to save commit points for replication, the SolrDeletionPolicy
//              // always saves the last commit point (and the last optimized commit point, if needed)
//              /***
//              if(indexCommitPoint != null){
//                core.getDeletionPolicy().saveCommitPoint(indexCommitPoint.getVersion());
//              }
//              ***/
//            }
//          }
//          if (core.getUpdateHandler() instanceof DirectUpdateHandler2) {
//            ((DirectUpdateHandler2) core.getUpdateHandler()).forceOpenWriter();
//          } else {
//            LOG.warn("The update handler being used is not an instance or sub-class of DirectUpdateHandler2. " +
//                    "Replicate on Startup cannot work.");
//          } 
//
//        } catch (IOException e) {
//          LOG.warn("Unable to get IndexCommit on startup", e);
//        } finally {
//          if (s!=null) s.decref();
//        }
//      }
//      String reserve = (String) master.get(RESERVE);
//      if (reserve != null && !reserve.trim().equals("")) {
//        reserveCommitDuration = SnapPuller.readInterval(reserve);
//      }
//      LOG.info("Commits will be reserved for  " + reserveCommitDuration);
//      isMaster = true;
//    }
//  }
//  
//  // check master or slave is enabled
//  private boolean isEnabled( NamedList params ){
//    if( params == null ) return false;
//    Object enable = params.get( "enable" );
//    if( enable == null ) return true;
//    if( enable instanceof String )
//      return StrUtils.parseBool( (String)enable );
//    return Boolean.TRUE.equals( enable );
//  }
//
//  /**
//   * register a closehook
//   */
//  private void registerCloseHook() {
//    core.addCloseHook(new CloseHook() {
//      @Override
//      public void preClose(SolrCore core) {
//        if (snapPuller != null) {
//          snapPuller.destroy();
//        }
//      }
//
//      @Override
//      public void postClose(SolrCore core) {}
//    });
//  }
//
//  /**
//   * A ResponseWriter is registered automatically for wt=filestream This response writer is used to transfer index files
//   * in a block-by-block manner within the same HTTP response.
//   */
//  private void registerFileStreamResponseWriter() {
//    core.registerResponseWriter(FILE_STREAM, new BinaryQueryResponseWriter() {
//      public void write(OutputStream out, SolrQueryRequest request, SolrQueryResponse resp) throws IOException {
//        FileStream stream = (FileStream) resp.getValues().get(FILE_STREAM);
//        stream.write(out);
//      }
//
//      public void write(Writer writer, SolrQueryRequest request, SolrQueryResponse response) throws IOException {
//        throw new RuntimeException("This is a binary writer , Cannot write to a characterstream");
//      }
//
//      public String getContentType(SolrQueryRequest request, SolrQueryResponse response) {
//        return "application/octet-stream";
//      }
//
//      public void init(NamedList args) { /*no op*/ }
//    });
//
//  }
//
//  /**
//   * Register a listener for postcommit/optimize
//   *
//   * @param snapshoot do a snapshoot
//   * @param getCommit get a commitpoint also
//   *
//   * @return an instance of the eventlistener
//   */
//  private SolrEventListener getEventListener(final boolean snapshoot, final boolean getCommit) {
//    return new SolrEventListener() {
//      public void init(NamedList args) {/*no op*/ }
//
//      /**
//       * This refreshes the latest replicateable index commit and optionally can create Snapshots as well
//       */
//      public void postCommit() {
//        IndexCommit currentCommitPoint = core.getDeletionPolicy().getLatestCommit();
//
//        if (getCommit) {
//          // IndexCommit oldCommitPoint = indexCommitPoint;
//          indexCommitPoint = currentCommitPoint;
//
//          // We don't need to save commit points for replication, the SolrDeletionPolicy
//          // always saves the last commit point (and the last optimized commit point, if needed)
//          /***
//          if (indexCommitPoint != null) {
//            core.getDeletionPolicy().saveCommitPoint(indexCommitPoint.getVersion());
//          }
//          if(oldCommitPoint != null){
//            core.getDeletionPolicy().releaseCommitPoint(oldCommitPoint.getVersion());
//          }
//          ***/
//        }
//        if (snapshoot) {
//          try {
//            SnapShooter snapShooter = new SnapShooter(core, null);
//            snapShooter.createSnapAsync(currentCommitPoint, ReplicationHandler.this);
//          } catch (Exception e) {
//            LOG.error("Exception while snapshooting", e);
//          }
//        }
//      }
//
//      public void newSearcher(SolrIndexSearcher newSearcher, SolrIndexSearcher currentSearcher) { /*no op*/}
//    };
//  }
//
//  private class FileStream {
//    private SolrParams params;
//
//    private FastOutputStream fos;
//
//    private Long indexVersion;
//    private IndexDeletionPolicyWrapper delPolicy;
//
//    public FileStream(SolrParams solrParams) {
//      params = solrParams;
//      delPolicy = core.getDeletionPolicy();
//    }
//
//    public void write(OutputStream out) throws IOException {
//      String fileName = params.get(FILE);
//      String cfileName = params.get(CONF_FILE_SHORT);
//      String sOffset = params.get(OFFSET);
//      String sLen = params.get(LEN);
//      String compress = params.get(COMPRESSION);
//      String sChecksum = params.get(CHECKSUM);
//      String sindexVersion = params.get(CMD_INDEX_VERSION);
//      if (sindexVersion != null) indexVersion = Long.parseLong(sindexVersion);
//      if (Boolean.parseBoolean(compress)) {
//        fos = new FastOutputStream(new DeflaterOutputStream(out));
//      } else {
//        fos = new FastOutputStream(out);
//      }
//      FileInputStream inputStream = null;
//      int packetsWritten = 0;
//      try {
//        long offset = -1;
//        int len = -1;
//        //check if checksum is requested
//        boolean useChecksum = Boolean.parseBoolean(sChecksum);
//        if (sOffset != null)
//          offset = Long.parseLong(sOffset);
//        if (sLen != null)
//          len = Integer.parseInt(sLen);
//        if (fileName == null && cfileName == null) {
//          //no filename do nothing
//          writeNothing();
//        }
//
//        File file = null;
//        if (cfileName != null) {
//          //if if is a conf file read from config diectory
//          file = new File(core.getResourceLoader().getConfigDir(), cfileName);
//        } else {
//          //else read from the indexdirectory
//          file = new File(core.getIndexDir(), fileName);
//        }
//        if (file.exists() && file.canRead()) {
//          inputStream = new FileInputStream(file);
//          FileChannel channel = inputStream.getChannel();
//          //if offset is mentioned move the pointer to that point
//          if (offset != -1)
//            channel.position(offset);
//          byte[] buf = new byte[(len == -1 || len > PACKET_SZ) ? PACKET_SZ : len];
//          Checksum checksum = null;
//          if (useChecksum)
//            checksum = new Adler32();
//          ByteBuffer bb = ByteBuffer.wrap(buf);
//
//          while (true) {
//            bb.clear();
//            long bytesRead = channel.read(bb);
//            if (bytesRead <= 0) {
//              writeNothing();
//              fos.close();
//              break;
//            }
//            fos.writeInt((int) bytesRead);
//            if (useChecksum) {
//              checksum.reset();
//              checksum.update(buf, 0, (int) bytesRead);
//              fos.writeLong(checksum.getValue());
//            }
//            fos.write(buf, 0, (int) bytesRead);
//            fos.flush();
//            if (indexVersion != null && (packetsWritten % 5 == 0)) {
//              //after every 5 packets reserve the commitpoint for some time
//              delPolicy.setReserveDuration(indexVersion, reserveCommitDuration);
//            }
//            packetsWritten++;
//          }
//        } else {
//          writeNothing();
//        }
//      } catch (IOException e) {
//        LOG.warn("Exception while writing response for params: " + params, e);
//      } finally {
//        IOUtils.closeQuietly(inputStream);
//      }
//    }
//
//
//    /**
//     * Used to write a marker for EOF
//     */
//    private void writeNothing() throws IOException {
//      fos.writeInt(0);
//      fos.flush();
//    }
//  }
//
//  public static final String MASTER_URL = "masterUrl";
//
//  public static final String STATUS = "status";
//
//  public static final String COMMAND = "command";
//
//  public static final String CMD_DETAILS = "details";
//
//  public static final String CMD_BACKUP = "backup";
//
//  public static final String CMD_FETCH_INDEX = "fetchindex";
//
//  public static final String CMD_ABORT_FETCH = "abortfetch";
//
//  public static final String CMD_GET_FILE_LIST = "filelist";
//
//  public static final String CMD_GET_FILE = "filecontent";
//
//  public static final String CMD_FILE_CHECKSUM = "filechecksum";
//
//  public static final String CMD_DISABLE_POLL = "disablepoll";
//
//  public static final String CMD_DISABLE_REPL = "disablereplication";
//
//  public static final String CMD_ENABLE_REPL = "enablereplication";
//
//  public static final String CMD_ENABLE_POLL = "enablepoll";
//
//  public static final String CMD_INDEX_VERSION = "indexversion";
//
//  public static final String CMD_SHOW_COMMITS = "commits";
//
//  public static final String GENERATION = "generation";
//
//  public static final String OFFSET = "offset";
//
//  public static final String LEN = "len";
//
//  public static final String FILE = "file";
//
//  public static final String NAME = "name";
//
//  public static final String SIZE = "size";
//
//  public static final String LAST_MODIFIED = "lastmodified";
//
//  public static final String CONF_FILE_SHORT = "cf";
//
//  public static final String CHECKSUM = "checksum";
//
//  public static final String ALIAS = "alias";
//
//  public static final String CONF_CHECKSUM = "confchecksum";
//
//  public static final String CONF_FILES = "confFiles";
//
//  public static final String REPLICATE_AFTER = "replicateAfter";
//
//  public static final String FILE_STREAM = "filestream";
//
//  public static final int PACKET_SZ = 1024 * 1024; // 1MB
//
//  public static final String RESERVE = "commitReserveDuration";
//
//  public static final String COMPRESSION = "compression";
//
//  public static final String EXTERNAL = "external";
//
//  public static final String INTERNAL = "internal";
//
//  public static final String ERR_STATUS = "ERROR";
//
//  public static final String OK_STATUS = "OK";
//
//  public static final String NEXT_EXECUTION_AT = "nextExecutionAt";
//  
//  public static final String NUMBER_BACKUPS_TO_KEEP = "numberToKeep";
//}
